This sentence is funny for several reasons, not least of which is it comes after a long list of pre-electronics calculators.
The mention of dead reckoning totally reminded me of one of the coolest math books I ever bought, and I think I first heard about it in a comment here on HN. Maybe I can pass this recommend on to someone else who will appreciate it. “Dead Reckoning: Calculating Without Instruments” by Ronald Doerfler https://www.amazon.com/Dead-Reckoning-Calculating-Without-In...
It covers how to do lots of calculations very efficiently mentally or manually on paper, not just arithmetic but roots and powers, logarithms and exponents, and trig functions (sin,cos,tan,asin,acos,atan). Lots of interesting number theory, lots of stuff that’s useful in computer science, and a tour de force of the most important analog calculator this article didn’t cover: the human calculator. ;)
Here's a fantastic book on the subject:
https://www.amazon.com/Dead-Reckoning-Calculating-Without-In...
Hartzler, "A two-and-one-half-place logarithm table", The Mathematics Teacher, Vol. 53, No. 3 (Mar 1960) https://www.jstor.org/stable/27956101
Bayer, "Setting up an approximate antilog table", The Mathematics Teacher, Vol. 55, No. 3 (Mar 1962) https://www.jstor.org/stable/27956560
Doerfler, "Dead Reckoning: Calculating Without Instruments", Taylor Trade Publishing (Sep 1993) https://www.amazon.com/Dead-Reckoning-Calculating-Without-In...